The director general of the Wada, David Howman, says that 36 positive cases of EPO out of 258,000 in 2010 is 'very disappointing'. Photograph: Jean-Christophe Bott/EPA

Less than six months before London 2012, the World Anti-Doping Agency fears that fewer than one in five drug cheats is being caught and urged against complacency from governments and sporting bodies in tackling the problem.

David Howman, the Wada director general, said that despite ever more sophisticated testing, a major research project undertaken by the global body had indicated more than one in 10 athletes were tempted to cheat but only between 1% and 2% were caught.

"We think the annual statistics show that maybe between 1 and 2% of athletes who are tested are cheating. By conducting these research projects, the results of which will be made known later this year, we think those numbers are more into double digits," said Howman.

"That's a concern. If more than 10% of the athletes in the world are being tempted to take a shortcut via taking prohibited substances then we've got an issue that is not being confronted as well as it should be."

London 2012 organisers recently unveiled the most comprehensive testing programme in the history of the Games and warned that cheats would almost certainly be caught.

But Wada said that while athletes who cheated in major events were likely to be caught, outside of competition too many tests were being conducted "selectively" with more expensive blood tests for EPO and human growth hormone not being carried out often enough.

"You can't test for human growth hormone unless you get a blood sample. In 2010, of the 258,000 samples collected there were 36 positive tests for EPO," said Howman. "EPO is probably one of the preferred substances of those athletes taking shortcuts and to have only 36 positives in one year is very disappointing."

It is feared that of the 258,000 tests conducted, as few as 2% of them include the blood tests that can catch the use of human growth hormone.

The scale of the problem is being masked by the fact that in many cases the contracts between anti-doping organisations (ADOs) and laboratories are confidential. Too many were testing for a "selected menu" of drugs rather than the "full menu", said Howman.

"We need ADOs to use the full menu because at the moment there is not as much testing for some substances as we need," he said.

Wada welcomed this week's court of arbitration for sport judgment in the Alberto Contador case, in which the Spanish cyclist was banned for two years and stripped of his 2010 Tour de France title. The decision backed Wada's "strict liability" stance.

The Wada president, John Fahey, said: "I think it indicates clearly the robust nature of our code following a comprehensive review of significant evidence. Our code was upheld in strong terms.

"There is a strong message in that – the onus is on athletes to ensure that they don't take substances that can lead to an outcome such as the one we've seen." He added: "Every time a cheat is caught it is a good day for sport."

But Howman and Fahey, also warned that "anti-doping fatigue" could impact on the battle to catch "sophisticated" dopers, particularly as governments and policy makers considered the new scourge of illegal betting and related corruption.

"In times of economic hardship other issues start to occupy the ground we try to keep for anti-doping. Anti-doping fatigue can set in," said Fahey. "We need governments to accept anti-doping is not just an issue for sport, it is an issue for society. We need champions in government and sport to stand up for clean competition."

Wada is increasingly working with Interpol, law enforcement and customs agencies to attempt to infiltrate those who traffic and supply prohibited substances.

Howman appealed to the sports industry to make a direct contribution to Wada's £17.8m budget, funded equally by the International Olympic Committee and national governments but recently frozen in light of the global economic downturn.

"We are harsh critics of our standards and conscious of the costs involved in testing. Wada has always been equally part-funded by the IOC and governments and maybe the time has come for Wada to look elsewhere for contributions," he said. "The global sports industry is not short of money – $500bn (£315bn) per annum. Perhaps that global sports industry should consider making a direct financial contribution."

Fahey said it was looking into establishing a foundation where high earning sports stars could contribute to Wada's budget.

In March, the Cas will rule on whether Wada was right to rule the British Olympic Association non-compliant with its anti-doping code over its bylaw that bans drug cheats for life. Fahey said Wada had "conscientiously and rightfully" declined to comment on the facts of the case until after it had been heard and said it was a "matter of regret" that the BOA chairman, Lord Moynihan, continued to do so.

The issue has sparked a huge row between the two bodies, with Fahey again criticising Moynihan's "misinformed and inaccurate tirade" against his organisation.

Wada also urged US federal prosecutors to hand over evidence collected during a long-running probe into the American cyclist Lance Armstrong, which was this week dropped. "The inquiry in the US was about fraud, but the evidence that has been gathered was about doping. We expect the evidence will be shared in the same way [as in the Balco case]," said Howman.

"It is important that happens as quickly as possible, just in case there might be athletes who are going to London to whom it might refer."

Howman also called for more to be done to take effective sanctions against those who surround athletes who cheat, and in some cases pressure them to do so. "Often the athlete is persuaded and cajoled by people who should know better. It doesn't take much to realise how effective an entourage can be," he said.

"How many lawyers have been pulled before a law society disciplinary committee? How many doctors have gone to medical tribunals? That's the level we need to look at. It is very easy to catch the dopey doper. The sophisticated doper is becoming harder to detect and that's a big challenge for the anti-doping movement."